Deposed at the Second Council of Ephesus in 449 accompanied by shouts of ‘Ibas to the mines’, but then reinstated two years later at the Council of Chalcedon, Bishop Ibas of Edessa lived in turbulent theological times. The lively proceedings against him in 449 (now available in English translation in R. Doran's Stewards of the poor, 2006) make for colourful reading, and his Letter to Mari, accepted as an authoritative document at Chalcedon, subsequently proved something of an embarrassment to the Neo-Chalcedonians of the early sixth century, eventually to be openly condemned in 553 at the Council of Contstantinople. Although in modern times Ibas is probably less well known than his predecessor Rabbula, he is in many ways a more interesting figure for the historian, given the number of very different attitudes to him to be encountered in the sources; accordingly it is most welcome now to have for the first time a monograph devoted to him. Claudia Rammelt's book, which is a revised version of her Göttingen dissertation, provides a thorough and careful study of the subject. Successive chapters are devoted to the background of Edessa, the biographical notices, his Letter to Mari, his place in the theological controversies of the years between the First Council of Ephesus (431) and Chalcedon, and his reception in course of the following century or so, with a brief final glance at some of the varying attitudes to him that are still reflected in modern ecumenical dialogue. Rammelt is primarily concerned with the more theological aspects of Ibas's career, although she is also aware that there might well also have been other issues at stake in the conflict between Ibas and supporters of Rabbula, in particular different attitudes to emergent monasticism in the diocese. These other issues, including more specifically social ones, certainly deserve further exploration, but Rammelt's monograph has provided a solid basis for all further study of this bishop of Edessa who aroused such passions.